XML Glossary

CSS (Cascading Style Sheets): Method of defining document elements such as headings, fonts and colours using style rules instead of extra markup tags.

content: Content is all data between the start tag and end tag of an element. Content may be made up of markup characters and character data.

DTD: A DTD is a Document Type Definition. This sets out the rules that are used to define the tags in a particular XML file and their valid values.

MathML (Mathematical Markup Language): This is a use of XML to describe mathematical notations on Web documents, just as HTML does for ordinary text.

parser: An XML parser is a processor that reads an XML document and determines the structure and properties of the data. If the parser goes beyond the XML rules for "well-formedness" and validates the document against an XML DTD, the parser is said to be a validating parser.

XML vocabulary: This is an XML tag set with a specific functionality such as MathML. Other examples include SMIL, WIDL and ICE.

XSL (Extensible Style Language): How to specify the presentation and appearance of an XML document, the way CSS does for ordinary HTML documents.